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--- data:data_analysis_manual [2021/09/30 11:24]
eric buchlin Fix formatting
+++ data:data_analysis_manual [2022/08/27 10:04]
eric buchlin [Find data] link to using the catalog in IDL
@@ Line 11: / Line 11: @@
 SPICE papers:
   * Instrument paper: //Astron. Astrophys.//, **642**, A14, 2020. [[https://doi.org/10.1051/0004-6361/201935574|DOI]], [[https://ui.adsabs.harvard.edu/abs/2020A%26A...642A..14S|ADS]]
-  * First results: Submitted
+  * First results: //Astron. Astrophys.//, **656**, A38, 2021. [[https://doi.org/10.1051/0004-6361/202141221|DOI]], [[https://ui.adsabs.harvard.edu/abs/2021A%26A...656A..38F/abstract|ADS]]
   * In-flight calibration: Not available yet
   * Other papers can be found in the [[https://ui.adsabs.harvard.edu/public-libraries/rIi8Zx4zTg2stP5nTojx2Q|SPICE ADS library]]
@@ Line 27: / Line 27: @@
 The full SPICE data set (to be cited in papers) has a DOI: [[https://doi.org/10.5270/esa-lbmdy7c|doi:10.5270/esa-lbmdy7c]]. DOIs will also be attributed to each data release.
+When browsing the SPICE catalog and archive you will see the following codes:
+**n-ras**: a raster scan with one of the narrow slits (2", 4" or 6")\\
+**w-ras**: a raster scan with the wide slit (30")\\
+**n-sit**: a sit-and-stare study with one of the narrow slits\\
+**w-sit**: a sit-and-stare study with the wide slit\\
+**n-exp**: a single exposure with a narrow slit that yields the entire spectrum\\
+**w-exp**: a single exposure with the wide slit that yields the entire spectrum
+For the "ras" data, the FITS file contains a single raster scan. If the raster is repeated, then each repeat goes in a new file.
+Rasters can be performed in the "exp" mode, but each exposure will end up in a different FITS file.
 ===== Find data =====
@@ Line 36: / Line 49: @@
   * The catalogue file generated from all SPICE files is accessible [[http://astro-sdc-db.uio.no/vol/spice/fits/spice_catalog.txt|through the UiO website]] (restricted to SPICE team)
   * How to use it in [[data:data_analysis_manual:read_catalog_python|Python]]
+  * How to use it in IDL: [[data:data_analysis_manual#the_spice_catalog|see below]]
   * A CSV export of the part of the catalogue corresponding to each release is provided with the release.
@@ Line 47: / Line 61: @@
 In the future: VSO. VSO through SSW or sunpy. Sunpy/Fido
+===== Tips and Advice on Analyzing SPICE Data =====
+==== Doppler Maps ====
+WARNING: Doppler maps created from SPICE lines show unusual patterns that we believe are due to the point spread function of the instrument. Work is underway on a deconvolution procedure that will correct for this effect. If you need advice on features you see in a Doppler map, please contact the SPICE PI at frederic.auchere -at- universite-paris-saclay.fr or another member of the SPICE team.
+==== Burn-in Effects ====
+The SPICE detectors have microchannel plates (MCPs). Over time, the sensitivity of MCPs decreases at the locations of strong emission lines. This effect is referred to as "burn-in" and results in a flat-top or "self-reversal" to the line profile. This has already been noticed for the C III 977 line. The SPICE team plans to provide a correction to this effect once it is fully characterized.
+==== Flare lines ====
+The two key flare lines for EIS are Fe XVIII 974.86 and Fe XX 721.56 that are formed around 7 MK and 10 MK, respectively. The Fe XVIII line will probably be seen in active region cores (at least from bright active regions).
+The Fe XVIII line is located between the stronger H I 972.54 (Lyman-gamma) and C III 977.02, but measurements should be possible.
+The Fe XX line lies close to Fe VIII 721.26. One can estimate the strength of this line by comparing with Mg IX 706.06. The latter will be about a factor 10 stronger.
+To determine if a flare is occurring at the time of a SPICE observation, check the STIX Data Browser at:
+[[https://datacenter.stix.i4ds.net/view/plot/lightcurves
+]]
 ===== Access data =====
@@ Line 126: / Line 162: @@
 | d->get\_number\_windows()      | No. of spectral windows                |
 | d->get\_window\_data(i,/load)  | Extract a data window                  |
+| d->get\_lambda\_vector(i)      | Get wavelength vector for the window                  |
 | d->get\_header(i)              | Extract a data window header           |
 | d->get\_window\_id(i)          | Get the data window ID                 |
@@ Line 153: / Line 190: @@
 Use a 3-button mouse to browse the images and spectra: the middle button allows you to select a new pixel, the left button zooms in and the right button zooms out.
+===== Ephemeris information =====
+You can access ephemeris information from the SPICE headers. For example, the keywords:
+DSUN\_AU - distance of the spacecraft from the Sun in AU\\
+EAR\_TDEL - light travel time from the spacecraft to Earth (seconds)
+The full list of keywords is given in the [[https://spice.ias.u-psud.fr/spice-data/documents/SPICE-UIO-DPDD-0002-1.4-Data_Product_Description_Document.pdf|DPDD]] - search for "Solar ephemeris keywords".
+Users should make sure to correct the SPICE observing times for EAR\_TDEL in order to compare with observations from Earth-orbiting spacecraft. This is especially important for highly-dynamic structures such as flares or CMEs.
 ===== Read and display data (Python) =====

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